Description of Business and basis of presentation (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation Our condensed consolidated financial statements are unaudited; however, in the opinion of management, they contain all of the adjustments (consisting of those of a normal, recurring nature) considered necessary to present fairly the financial position, results of operations, and cash flows for the periods presented in conformity with U.S. generally accepted accounting principles ("U.S. GAAP") applicable to interim periods. All significant intercompany accounts and transactions have been eliminated in consolidation. The Company consolidates entities that it controls due to ownership of a majority voting interest. The unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020.
Use of estimates	Use of estimates The preparation of the financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the unaudited condensed consolidated financial statements and footnotes thereto. Actual results could differ from those estimates. Significant estimates inherent in the preparation of the condensed consolidated financial statements include pension and postretirement benefit obligation assumptions, income taxes, goodwill and intangible asset impairment analysis, valuation of property, plant and equipment and intangible assets and the mark to market of the conversion feature associated with the convertible debt.
Recent accounting pronouncements adopted and Recent accounting pronouncements not yet adopted	Recent accounting pronouncements adopted Simplifying the Accounting for Income Taxes In December 2019, the Financial Accounting Standards Board (the "FASB") issued new guidance that simplifies the accounting for income taxes. The guidance amends the rules for recognizing deferred taxes for investments, performing intraperiod tax allocations and calculating income taxes in interim periods. It also reduces complexity in certain areas, including accounting for transactions that result in a step-up in the tax basis of goodwill and allocating taxes to members of a consolidated group. This guidance is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. Adopting this guidance allowed us to record a tax benefit for the quarter because year-to-date losses on interim periods are no longer limited to losses annually forecasted. Recent accounting pronouncements not yet adopted Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity In August 2020, the FASB issued new guidance ("ASU 2020-06") that simplifies the accounting for convertible instruments by reducing the number of accounting models for convertible debt instruments and convertible preferred stock. In addition to eliminating certain accounting models, the guidance amends the disclosures for convertible instruments and earnings-per-share guidance. It also amends the guidance for the derivatives scope exception for contracts in an entity’s own equity to reduce form-over-substance-based accounting conclusions. This guidance is effective for fiscal years beginning after December 15, 2023, with early adoption permitted no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. The Company is evaluating the impacts that the adoption of ASU 2020-06 will have on our accounting for the 6.0% Senior Secured Convertible Notes due 2027 (the "2027 Notes"), and the impact on our condensed consolidated financial statements.